Question

Good evening mam/sir

My query is that...Reena climbs up 5 stairs in every second and then climb down 2 stairs over the next second . How many second will she take to climb 60 stairs..

Thank you

Answer 1

5 stairs added per 1 second
2 stairs deducted the next second
so every 2 seconds=5-2=3
stairs=60
stairs every 2 seconds=3
=60×3/2
=180/2
=90
:she will take 90 seconds